Medical ultrasound imaging is a well-established imaging technology for visualization of tissue morphology in various organs that provides diagnostic information based on analysis of anatomy. Optoacoustic imaging is used in medical applications for in vivo and in vitro mapping of animal and human tissues and organs based on variation in tissue optical properties. Optoacoustic tomography can provide anatomical, functional and molecular imaging, but the most significant value of optoacoustic imaging is in its capability to provide quantitative functional information based on endogenous contrast of molecular constituents of red blood cells. The essence of functional imaging is to provide the physician with a map of blood distribution and its level of oxygenation, so that the physician can determine whether particular tissue functions normally or not. For example, a map of total hemoglobin distribution simultaneously showing an area with increased concentration and decreased oxygen saturation indicates potential malignancy. The essence of molecular imaging is to provide maps of distributions and concentrations of various molecules of interest for a specific health condition. For example, distribution of specific protein receptors in cell membranes gives insight into molecular biology or cells that aids in designing drugs and therapeutic methods to treating human diseases.